Work has continued at a low level with occasional serological identification of new parvovirus isolates and the extension of various consultative services along with the provision of standardized virus and sera. A serological survey for the presence of parvovirus antibodies in AIDS patients has been initiated. Adenovirus-associated virus (AAV)-carrier cell clones continue to provide the basis for a study of the integration state of AAV. Soon after cloning no free viral DNA can be detected in such carrier clones. However after 60-100 cell transfers small amounts of unintegrated viral DNA is found. It has been further shown that passage of carrier cells under the condition of low serum concentration eliminates the inducibility the AAV carrier cells even though the presence of AAV-DNA can be detected by standard hybridization techniques.